Process for breaking petroleum emulsions



Patented Mar. 27, 1945 Melvin De Groote, University City, and Bernhard Keiser, Webster Groves, Mo., assignors to Petrolite Corporation, Ltd., Wilmington, DeL, a

corporation of Delaware No Drawing. Application June 23, 1943,

Serial No. $92,183

6 Claims. (Cl. 252-341) This inventionrelates primarily to the resolution of petroleum emulsions.

One object of our invention is to provide a novel process for resolving petroleum emulsions of the \water-in-oil type, that are commonly" referred to as cut oil, roily'oil," emulsified oil," etc., and which comprise fine droplets of naturally-occurring waters or brines dispersed in a more or less permanent state throughout the oil which constitutes the continuous phase of the emulsion.

Another object of our invention is to provide an economical and rapid process for separating emulsions which have been prepared under controlled conditions from mineral oil, such as crude petroleum and relatively soft waters or weak brines. Controlled emulsification and subsequent demulsification under conditions just mentioned, is of significant value in removing impurities, particularly inorganic salts from pipeline oil.

The demulsifier or demulsifying agent em-' played in our process consists of certain pyridinium compounds containing Ta) a high molal monocarboxy acyl radical; and (b) a urea nucleus.

The type of chemical compound herein contemplated, as far as its'major aspect is concerned, may be obtained in the following manner: urea or a substituted urea, and particularly a monoalkyl or dialkyl urea, is treated with an oxyalv kylating agent, such as ethylene oxide, so as to introduce atleast two hydroxyl radicals, preferably as separate oxyalkvlene or poly-oxyalkylene radicals. Such polyhydric urea derivative is then esteriiied with a high molal monccarboxy acid having at least 8 carbon atoms and not more than 32 carbon atoms. The high molal monocarboxy acids may be exemplified by the higher fatty acids; The esterification is conducted so that there is present at least one unesterifled hydroxyl radical. Such esterifled oxyalkylated urea or oxyalkylated substituted urea, is reacted with one or more moles of ,a pyridine hydrohalide, such as pyridine hydrochloride, or its equivalent, so as to obtain the new compound or composition of matter herein contemplated." The method of preps nation and the structure of the compound will be described subsequently in greater detail.

It is well known that certain pyridinium compounds are obtainable by reactions involving the elimination of a mole of water formed by reaction between a pyridinium hydrogen atom and the hydroxyl of a hyd'romthyl group or the like.

. (For example, see U. 8. Patent No. 2,373,181, datedalso U. s. Patent N0.(2,290,417, dated July 21, 1942,

to De Groote and Keiser.)

It is well known that certain monocarboxy organic acids containing 8 carbon atoms or more,

and not more than 32' carbon atoms, are characterized by the fact that they combine with alkalis to produce soap or soap-like materials. These detergent-forming acids include fatty acids, resin acids, petroleum acids, etc. For the sake of convenience, these acids will be indicated by the formula R.COOH. Certain derivatives of'detergent-forming acids react with alkali to produce soap or soap-like materials, and are the obvious equivalent of the unchanged or unmodified detergent-forming acids; for instance, instead of fatty acids, one might employ the chlorinatedfatty acids. Instead of the resin acids, one might em ploy the hydrogenated resin acids. Instead of naphthenic acids,-0ne might employ brominated naphthenic acids, etc.

The fatty acids are pf-the type commonly referred to as higher fatty acids; and of course, this is also true in regard to derivatives of the kind indicated, insofar that such derivatives are obtained from higher fatty acids. The petroleum acids include not only naturally-occurring naphthenic acids, but also acids obtained by the oxidation of wax, paraflin, etc. Such acids may have as many as 32 carbon atoms. For instance,

see us. Patent No. 2242337, dated May 20, 1941, to Shields.

' We have found that by far the most effective demulsifying agents are obtained from unsaturated fatty acids having 18 carbon atoms. Such unsaturated fatty acids include the fatty acids,

such as oleic acid, ricinoleic acid, linoleic acid,

linolenic acid, etc. One may employ mixed fatty acids, as,for example, the fatty acids'obtained from hydrolysis of cottonseed oil, soyabean oil, corn oil, etc. Our preferred demulsi'fier is obtained from unsaturated fatty acids, and more especially, unsaturated fatty acids, containing a hydroxyl radical, or unsaturated fattyacids which have been subjected to an oxidation.

As to suitable reactants containinga reactive ethylene oxide ring, or the equivalent, reference is made to U. S. Patent No. 2,208,581, dated July 23, 1940, to Hoeffelmann. As typical examples of applicable compounds may be mentioned glycerine epichlorhydrin, glycide alcohol, ethylene oxide,

propylene oxide, butene-Z-oxide, buteneei-oxide,

February 17, i942, to De Groote and Keiser; and

isobutylene oxide, butadiene oxide, butadiene dioxide, chloroprene oxide, isoprene oxide, decene oxide, styrene oxide, cyclohexylene .oxide, CYClO-y pentene oxide, etc. 1 r

As to the reaction of ureas or substituted ureas, followed by esterification with a high molal hydroxy acid, reference is made to U. S. Patent No. 2,083,221, dated June 8, 1931, to DeGroote. (See also U. S. Patent No. 2,059,273, dated November 3, 1936, to Piggott.) It is to be noted that in light of present knowledge, there is considerable doubt that any free amino hydrogen atoms remain in presence of treatment with an excess of a reactant containing a reactive ethylene oxide ring. Furthermore, it is to be noted that the aforementioned patents are concerned with materials which are essentially soluble, i. e., watersoluble esterified oxyalkylated ureas or substituted ureas. In the present instance such esters need not be water-soluble. and as a matter of fact, we prefer to use the particular type of reactant which is water-insoluble prior to reaction with pyridine hydrochloride, or its equivalent. In other words, it is our preference that the solubility be obtained at least largely, and preferably, entirely through the introduction of the pyridinium radical or radicals.

Members'of the pyridine series suitable as reactants include pyridine, alkylated derivatives of pyridine, particularly alkylated derivatives in:

which the alkyl radical contains three carbon atoms or less, and especially methylated pyridines, i. e., pyridines in which one, two, or three methyl groups have been substituted in the nucleus, such as picolines, and collidines. Also suitable as reactants are the comparable quinolines and isoquinolines, along with C-methyl homologues thereof. Coal tar bases represent mixt r of suitable heterocyclic materials which may be used as'such, or after suitable purification, without separation into the individual components.

As to the reaction of ureas or substituted ureas, followed by esterification with a high molal hydroxy acid, reference is made to US. Patent No. 2,083,221, dated June 8, 1931, to De. Groote. (See also U.'S. Patent No. 2,059,273.)

OxYALKYLATno UREA DERIVATIVE Example 1 1 pound mole of 'ureais reacted with 4 pound moles of ethylene oxide at a temperature of ap proximately 100 C. for approximately 6 hours, with constant stirring, until all of the ethylene oxide is absorbed. The ethylene oxide need not be added at one time, but may 'be added intermittently. In such event, the period of reaction may be considerably longer. If desired, one-half of 12/2 of sodium methylate may be used as a cata ys OxYALKYLATnn UREA DERIVATIVE Example 2 The same procedure is followed as in Example 1, preceding, except that the amount of ethylene oxide employed per mole of urea is doubled.

OxYALxYLATEh UREA DERIVATIVE Eaample'3 I The same procedure is followed as in Example 1, preceding, except that the amount of ethylene oxide per mole is tripled.

OxYALmAm UREA DERIVATIVE Example 4 Diamyl urea is prepared from amylene and a cyanate. (See Berichte, 12, 1331 Custer.) Such substituted urea'is treated with ethylene oxide in the same manner as Examples 1, 2, and 3, preceding.

OxYALxrLATEn UREA DERIVATIVE Example 5 OxYALxYLATEn UREA DERIVATIVE Eatample 6 The same procedure is followed as in Example 4, preceding, except that the corresponding benzyl urea is substituted for diamyl urea.

OXYALKYLATED UREA DERIVATIVE Example 7 The same procedure is iollowed as in Example 4, preceding, except that the corresponding phenyl urea is substituted for diamyl urea.

OxYALxYLATED U EA DERIVATIVE Example. 8

N-mono-n-butyl urea CAHQHNCONHz is substituted for amyl urea in Example 4, preceding.

O'XYALKYLATED UREA DERIVATIVE Example 9 N,N-di-n-butyl urea (can) zNCONH: is substituted for amyl urea in Example 4, preceding.

OxYALKYiATEn UREA DERIVATIVE Example 11 N-mono-n-butyl thiourea C4H9NHCSNH2 is substituted for amyl urea in Example 4, preceding.

O'XYALKYLATED UREA DERIVATIVE Example 12 Other alkylene oxides, such as propylene oxide, butylene oxide, or glycidol, are substituted for ethylene oxide in Examples 1 to 11, preceding.

EsTERs or OXYALKYLATED UREA DERIVATIVES Example 1 Oxylated urea derivatives, as exemplified by Examples 1 to 12, preceding, are esterified with oleic acid in equimolar proportions, to give the desired ester. (See procedure described in aforementioned De Groote Patent No. 2,083,221).

EsTE s or OxYALxYLATEn UREA DERIVATIVES Example 2 Ricinoleic acidis substituted for oleic acid in Example 1, preceding.

EsTERs or OXYALKYLATED UREA DERIVATIVES Example 3 I Stearic acid is substituted for oleic acid in "Example 1, preceding.

ESTERS or OxYAtxYLATEn UREA DERIVATIVEs Example 4 Naphthenic acids derived from Gulf Coast crude petroleum are substituted for oleic acid in Example 1, preceding.

Esrlas or oxrarxrm'rrn Urns DsnIvArIves Example 5 Mixed fatty acids derived from soybean oil are substituted for oleic acid in Example 1, preced Esrsss or OxYALKYLAnm UREA DERIVATIVES Example 6 Linseed oil fatty acids are substituted for oleic acid in mample 1, preceding.

Brass or QXYALKYLATED UREA DERIVATIVES Example 7 In the preceding examples where there are present at least 3 hydrowl radicals, and preferably, 4 hydroxyl radicals, 2 moles of the fatty acids are employed instead of a single mole.

Pimmn nnu Comrourm Example 1 1 mole of urea is treated with 4 moles of ethylone oxide to give tetraethanol urea of the 101-.

lowing formula:

oncm. o canon /N- -c-N\ 011cm. 7 0.11.011

Such material is then esterifled with a mole ofricinoleic acid indicated by the formula R.COOI-I,

to give the resultant ester of the following composition:

oncnn 0111,0001:

one pound mole of an ester of the described immediately preceding is mixed with one pound mole of a hydrochloride of a fraction of pyridine m (50% distilling, up to 140 C., 90% distilaction employed may be indicated as follows:

" m malwlated urea derived by treating a,

mole oi N-mono-n-butyl urea cimmzcoum with three moles of ethylene oxide is reacted in the same manner as in Example 1, preceding.

Examples one pound mole of N,N'-di-n-butyl urea (CAHQ)HNCONH(C4H9) is treated with two pound moles of ethylene oxide and substituted as a reactant the procedure outlined in Ex- Example 4 One pound mole of N,N-di-n-butyl urea (C4Hol2NCONH: is treated with 2 pound moles of ethylene oxide and substituted as a reactant inthe procedure outlined in Example 1, precedi118.

Example 5 The same procedure is followed as in Examples 1 to 4, preceding, except that the amount of ethylene oxide employed is doubled.

Example 6 The same procedure is followed as in Examples 1 to 4, preceding, except that the amount of ethylene oxide employed'is tripled.

Example 7 The same procedure is followed as in Examples 1 to 6, preceding, except that propylene oxide, butylene oxide, or glycid is substituted for ethylene oxide in Examples 1 to 6, precedingk Example 8 The same procedure is followed as in Example 1, preceding, except that the esterification involves 2 moles of ricinoleic acid for each mole of tetrahydrowethyl urea.

Example 9 The same procedure is employed as in Example 1, preceding, except that the amount of pyridine hydrochloride per mole of tetrahydroxyethyl urea is doubled.

Example 10 The same procedure is followed in preceding Examples 1 to 9, inclusive, except that one substitutes instead the'various esters of oxyalkylated "urea derivatives exemplified by Examples 1 to 7,

preceding, to the extent that they are diiierent from the type already employed in Examples ,1 to 9, preceding.

In light of what has been said, it is obvious that-the invention may be considered in a somewhat broader aspect. For instance, urea might be treated with two moles of vethylene oxide so as to yield a diethanol urea.- Such a product would be perfectly satisfactory as a reactant.

The substituted ureas are not necessarily limited to the alkyl type, but as has been suggested previously, any hydrocarbon radical may serve as a substituent for an amino hydrogen atom. In other words, one or more of the amino hydrogen atoms, as indicated, may be replaced by an alkyl radical, an aryl radical, an aralhvl radical, or an alicycllc radical. In some instances, such substituted ureas are available by reactions involving primary amines and diethyl carbonate, although unfortunately, the yields are extremely low, even when conducted under pressure, or even when conducted in some other suitable manner. It has been pointed out that the oxyalkylating agent includes glycide and the like. Hereinafter, and particularly in the claims, reference will be made to the alkylene oxides as alkylating agents, and

more particularly, in those instances where the number of carbon atoms in the alkylene radical is less than ten, and preferably, not over four. The other variants previously indicated are obvious functional equivalents. Furthermore, the number of times that the ether linkage may occur is not limited, except that obviously there is no need for recurrence beyond the amount necessary to produce a water-soluble ester. However, as

previously stated, our preference is that the ester, prior to treatment with pyridine hydrochloride or the like, by Water-insoluble. Thus, it is preferred that the recurring ether linkage appear not over ten times. Previous reference has been made to the anion in the form of a halogen ion. Actually, any other suitable salt may appear as the anion, for instance, a nitric acid radical, an alkyl sulfuric acid radical, a trichloroacetic 'acid radical, asulfonic acid radical, etc. In many cases, the most desirable type of material is obtained from a high molal surface-active sulfonic acid acting as the anion. As to the various high molal sulfonic acids which may serve to furnish the anion, reference is made to U. S. Patent No. 2,295,167, dated September 8, 1942, to De Groote and Keiser. ployed is to neutralize pyridine or the equivalent with a selected sulfonic acid and then react the pyridine hydrosulfonate in the same manner as one would employ a pyridine'hydrohalide. Another procedure, of course, simply involves the principle of metathesis. produced in the manner previously described is reacted with the sodium sulfonate in an alcoholic solution, or, in some instances, in an aqueous solution. If the resultant' compound, i. e., a compound wherein the anion is the sulfonic acid radical, is water-insoluble, then precipitation takes place in aqueous solution. If, on the other hand, the resultant is water-soluble, then combination takes place in alcoholic solution by precipitation of sodium chloride, which can be removed and. the alcoholic solution distilled to eliminate the" solvent. Such procedures are described in considerable detail in our co-pending applications Serial Nos. 463,438 and 463,439, both filed October 26, 1942.

It should be noted that the variety of compounds herein contemplated for use as demulsifi'ers, may vary from water-insoluble materials to water-soluble materials. They may show various intermediate properties, i. e., some of the compounds may be water-wettable, some may be self-emulsifiable, some may produce cloudy solutions and others may produce clear solutions. Some may be oil-soluble and some may be oil and water-soluble. Some mayshow limited solubility in either oil or water.

In light of whathas been said, the compounds herein contemplated may be represented by the following formula, in conjunction with the obvious equivalents previously referred'to:

in which RC is the acyl radical of a monocarboxy detergent-forming acid having at least 8 and not over 32 carbon atoms; RrEN represents a radical derived from a heterocyclic compound consisting of pyridine, quinoline, isoquinoline, and C-methyl linked homologues thereof, and R2 and R3 are members of the class consisting of hydrogen atoms, alkyl radicals, aryl radicals, aralkyl radicals, alicyclic radicals, or either a anion (o.m..o -..o..n,...Ns m radical or a (CnHZnO) m.OCR

radical; 111. represents a small whole number not Briefly stated, the procedure emcular formula depicted is intended to include all the various isomeric forms and is not limited to the particular isomer shown. This is true insofar that isomers are all functional equivalents, and are, in fact, metamers. Any other treatment would result in a more involved claim, and

" perhaps detract from clarity.-

The pyridim'um chloride Conventional demulsifying agents employed in the treatment of oil field emulsions are used as such, or after dilution with any suitable solvent, such as water, petroleum hydrocarbons, such as gasoline, kerosene, stove oil; a. coal tar product, such as benzene, toluene, xylene, tar acid oil, cresol, anthracene oil, etc. Alcohols, particularly aliphatic alcohols, such as methyl alcohol, ethyl alcohol, denatured alcohol, propyl alcohol, butyl alcohol, hexyl alcohol, octyl alcohol, etc.,-may be employed as diluents. Miscellaneous solvents, such as pine oil, carbon tetrachloride, sulfur dioxide extract obtained in the refining of petroleum, etc., may-be employed-as diluents. Similarly, the material or materials employed as the demulsifying agent of our process may be admixed with one or more of the solvents customarily used in connection with conventional demulsifying agents. Moreover, said material or materials may be used alone, or in admixture with other suitable well known classes of demulsifying agents.

It is well known that conventional demulsifying agents may be used in a water-soluble form,

agents aresometimes used in a ratio of 1 to 10,000, or'1 to 20,000, or even 1 to 30,000, such an apparent insolubility in oil and water is not significant, because said reagents undoubtedly have solubility within the concentration employed. This same fact is true in regard to the material or materials employed as the demulsifying agent of our process.

We desire to point out that the superiority of the reagent or demulsifying agent contemplated in our process is based upon its ability to treat certain emulsions more advantageously and at a somewhat lower cost than is possible with other available 'demulsifiers, or conventional mixtures thereof. It is believed that the particular demulsii'ying agent or treating agent herein described will find comparatively limited application, so far as the majority of oil field emulsions are concerned, but we have found that such a. demulsifying agent has commercial value, as it will economically break or resolve oil field emul sions in a number of cases which cannot be treated as easily or at so low a. cost with the demulsifying agents heretofore available.

In practising our process for resolving petroleum emulsions of the water -in-oil type, a treating agent or demulsifying agent of the kind above described is brought into contact with or caused to act upon the emulsion to be treated, in any of the various ways, or by any of the various apps ratus now generally used to resolve or break petroleum emulsions with a chemical reagent, the above procedure being used either alone, or in combination with other demulsifying procedure, such as the electrical dehydration process.

The demulsifier herein contemplated may be employed in connection with what is commonly known as down-the-hole procedure, i. e., bringing the demulsifier in contact with the fluids of the well at the bottom of the well, or at some point prior to the emergence of said well fluids. This particular type of application is decidedly feasible when the demulsifier is used in connection with acidification of calcareous oil-bearing strata, especially if suspended in or dissolved in the acid employed for acidification.

' The chemical products or compounds-herein described constitute the subject-matter of our divisional application Serial No; 530,045, filed April 7, 1944. I

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a desmulsifler comprising an urea pyridinium compound of radicals, m represents a small whole number not greater than 10, n represents a small whole number greater than one and not greater than 10 and m represents an integer varying from 0 to 10.

greater than 10, 'n represents a small whole number greater than one and not greater than 10 and m represents an integer varying from 0 to 10.

3. A process for breaking petroleum emulsions of the water-in-oil typ which consists in subjecting the emulsion to the action of a demulsifier comprising an urea pyridinium compound of the formula:

anion in which RC0 is the acyl radical of an unsature 'ated higher fatty acid having at least 8 and not over 32 carbon atoms; RiEN is a heterocyclic radical selected from the class consisting of pyridine radicals, quinoline radicals, isoquinoline radicals, and C-methyl linked homologues thereof; R2 and R3 are members of the class consisting of hydrogen atoms, alkyl radicals, aryl radicals, aralkyl radicals, alicyclic radicals, and

alnion (0.11m .o.m..;N 1h. o,. n,.o)..'.oon

radicals i m represents 'a small whole number not greater than 10, n represents a small whole number greater than one and not greater than 10 and m represents'an integer varying from 0 to 10.-

4. A process for breaking petroleum emulsions Q of the waterin-oil type, which consists in sub- I jecting the emulsion to the action of a demulsifier comprising an urea pyridinium compound of the in which RC0 is the acyl radical of an unsaturati ed higher fatty acid having 18 carbon atoms;

RrEN is a heterocyclic radical selected i'rom'the 2. A process-for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifier comprising an urea pyridinium compound of the formula:

anion in which R00 s the acyl radical of a, higher fatty acid having at least 8 and not over 32 carbon atoms; R1EN is a heterocyclic radical selected from the class consisting of pyridine radicals, quinoline radicals, isoquinoline radicals, and C-methyl linked homologues thereto; R2 and Rs are members of the class consisting of hydrogen.

atoms, alkyl radicals, aryl. radicals, aralkyl radi-- cals, alicyclic radicals, and

' anion (CnH:n )n. ,nH2n.N 5 R;

c..H..0),..'.0cR radicals, m represents a small whole number not greater class consisting of pyridine radicals, quinoline radicals, isoquinoline radicals, and C -methy1 linked homologues'ther'eof; R: and R3 are members of the class consisting of hydrogen atoms,

alkyl radicals, aryl radicak, aralkyl radicals, alicyclic radicals, and i anion V radicals; m represents a small whole number not an 10, n represents a small wholenumber greater than one and not greater than 10, and 11:. represents an integer varying from 0 to 10.

5. A process for breaking petroleum emulsions of the water-:in-oii type. which consists in subjecting the emulsion to the action of a' demulsi-,

-'f ier comprising an urea pyridinium compound of the formula: Y

anion 1 c c.m.o)-o.nl..rta al N- N v Ra mmiomoon in which RC0 is the acyl radical of an mm.-

rated higher fatty acid having 18 carbon atoms; RiEN is a heterocyclic radical selected from ..the class consisting of pyridine radicals, quinoline radicals. linked homologues thereof; R2 and Rs are members of the class consisting of-hydrogen atoms,

isoquinoline radicals, and C-methyl' alkyl radicals, aryl radicals, aralkyl radicals, ali cyclic radicals, and

' anion n :.O)-C Han-NZ R1 c..H=,.0),'.ocR

fier comprising a mono quaternary urea pyridinium compound of the formula:

anion in which RC0 is the acyl radical 01' an unsaturated higher fatty acid having 18 carbon atoms;- RiSN is a heterocyclic radical selected'i'rom the class consisting of pyridine radicals, quinoline radicals, isoquinoline radicals, and C-metliyl linked homologues thereof; R: and R: are members of the class consisting of hydrogen atoms, alkyl radicals, aryl radicals, aralkyl radicals, alicyclic radicals; and

radicals; m represents a small whole number not greaterthan 10, n is a small whole number varyvarying from 0 to 10.

NIELVIN 'DE GROOTE. BERNHARD KEISER. 

